Patients receive oral amoxicillin-clavulanate potassium 3 times daily and oral ciprofloxacin twice daily on admission to the hospital. Treatment continues for 7 days in the absence of clinical deterioration or unacceptable toxicity. Patients are assessed as inpatients after ≥ 24 and up to 72 hours after the first antibiotic dose. Patients showing clear response (i.e., symptomatic improvement irrespective of neutrophil recovery, temperature ≤ 37.8 C for 24 hours) and who continue to meet study eligibility criteria are randomized to 1 of 2 arms.